Preparation and characterization of MAO-Si3N4 composite coating on AZ31B magnesium alloy

Micro arc oxidation process was carried out on AZ 31 B magnesium alloy using alkaline silicate based bath at a constant current density of 0.04 A/cm2. Nano size silicon nitride (Si3N4) particles were added in the bath to obtain MAO- Si3N4 composite coatings. Plain oxide coatings were also prepared for comparison. The developed coatings were characterised for their surface morphology, composition, structure, roughness, nanohardness and wear resistance properties. Field Emission Scanning Electron Microscopy (FE-SEM) analysis of the coating exhibited the irregular porous structure with cracked morphology. Energy Dispersive Analysis of X-ray (EDX) over the surface of the composite coating showed the presence of O (42.8 wt.%), Si (13.2 wt.%), F (4.8 wt.%), Al (0.63 wt.%) and N (7.8 wt.%) with balance Mg respectively. XRD pattern obtained for composite coating revealed the characteristic peaks corresponding to Mg, MgO and Mg2SiO4. Apart from these peaks the presence of a low intensity peak corresponding to Si3N4 was also observed. Composite coating exhibited about 56% increase in nanohardness value (387 HV) compared to plain oxide coating (167 HV). Dry reciprocating wear test experiment was carried out for composite, plain oxide and substrate materials against alumina ball. Wear loss obtained for the composite is 3 times less (10 µms) compared to plain oxide coating which indicated improved wear resistance of the MAO-Si3N4 composite

Use of Pulse Oximetry Screening in Early Detection of Congenital Heart Disease

INTRODUCTION: Among all congenital malformations, congenital heart disease is a relatively common problem with an incidence of 5-8 in every 1000 live births1-9. Of this 25% will have critical congenital heart disease.9-12 Congenital heart disease account for about 10% of infant deaths and about half of deaths due to congenital malformations in developed countries2. Now a days even complex congenital heart disease can be treated with the appropriate surgical or catheter intervention13. Early diagnosis of congenital heart disease is important for a good clinical outcome. Unrecognized or delayed diagnosis of some severe congenital heart diseases can lead to cardiac failure, cardiovascular collapse, and even death14-18. However diagnosis of congenital heart disease in the first few days of life is difficult because of an initial lack of specific clinical signs2. Clinical examination remains the most frequently used method to diagnose congenital heart disease in new borns19-22. In particular the presence of a heart murmur can raise the suspicion of congenital heart disease. But routine neonatal clinical examination fails to detect more than 50% of infants with congenital heart disease 23. More than 55% of them have no murmur24 and most of them are discharged before a diagnosis can be made and readmitted with severe heart failure or cardiovascular collapse. AIM AND OBJECTIVES: 1.To detect the usefulness of pulse oximetry screening in early detection of congenital heart disease (CHD). 2. To evaluate combined pulse oximetry and clinical examination as a screening method for congenital heart disease (CHD) in asymptomatic newborns. DISCUSSION: Some babies born with a cardiac defect may appear healthy soon after birth and may be sent home before their cardiac defect is detected. These babies are at risk of developing serious complication within the first few days or weeks of life and may have significant morbidity and mortality. Routine pulse oximetry screening may help in early identification of these babies before they land up in complications. EFFECTIVENESS OF PULSE OXIMETRY SCREENING: In this study abnormal pulse oximetry was found in 24 babies of which 17 had CHD on echocardiography.5 babies had major CHD [ 1- Transposition of the Great Arteries(d-TGA),1- Pulmonary Atresia (PA), 1- Tricuspid Atresia (TA), 1- Tetralogy of Fallot (TOF), 1-ASD(OP) with AV canal defect], 12 babies had minor CHD[4-small ASD, 8-small PDA]. Out of 17 CHD babies, 5 babies had murmur [1-TOF,1-ASD(OP) with AV canal defect,3-small PDA] and 12 babies had no murmur. This study showed that pulse oximetry can detect CHD in asymptomatic new born babies which have been missed by routine clinical examination. Notably pulse oximetry identified cases of life threatening complex cyanotic CHD such as Transposition of great arteries (TGA), Tricuspid Atresia (TA), Pulmonary Atresia (PA), none of which had been detected clinically. Pure left‐to‐right shunts such as ventricular septal defect, atrial septal defect, or patent ductus arteriosus should not be detected by pulse oximetry, but some of these defects (5-17%) proved to be screen positive.10,37,75,104 This happened probably due to bidirectional shunting during early postnatal pulmonary hypertension. CONCLUSION: 1. This study indicates that pulse oximetry is a noninvasive, reliable and useful screening tool for an early detection of congenital heart diseases especially cyanotic congenital heart diseases. 2. The normal oxygen saturation (negative pulse oximetry screening) does not rule out CHD especially acyanotic congenital heart disease. 3. The prevalence of murmurs detected at routine examination of neonates is 1.48%. 4. About 69.4% murmurs were due to an underlying cardiovascular malformation. So detection of a cardiac murmur may be a clue to the presence of an underlying heart disease particularly in asymptomatic newborn. 5. The absence of a murmur does not exclude serious heart disease. 6. This study concludes that the combination of pulse oximetry and clinical examination results in early detection of CHD. Pulse oximetry has an additive effect and results in more efficient screening. 7. This study suggests that combined screening (pulse oximetry + cardiac clinical examination) should be used as a screening method for detection of CHD

Antiproteinuric effects of cilnidipine and amlodipine as add on therapy in hypertensive patients with chronic renal disease: a comparative study

Background: Cilnidipine is a dual blocker of L type and N type calcium channel and dilates both afferent and efferent arterioles. Hence it increases renal blood flow and reduces glomerular pressure ultimately reducing proteinuria. Thus, it may exert renoprotective effects. The present study was designed to compare the antiproteinuric effects of cilnidipine and amlodipine in hypertensive patients with chronic kidney disease as add on therapy to patients on losartan.Methods: This is a randomized, open label, prospective, parallel group study conducted in the out patient Department of Nephrology. The trial enrolled Diabetic CKD patients with hypertension and with spot urine protein creatinine ratio (PCR) ≥0.2 who were being treated with T. Losartan 50mg/day for >2 months. The subjects were then randomly assigned to 2 groups to receive either cilnidipine 10-20mg/day (Group A-46) or amlodipine 5-10mg/day (Group B- 50). The drugs were given for a duration of 6 months for each patient. The dose of losartan (50mg/day) was not adjusted throughout the study.Results: After 6 months, a significant reduction in systolic and diastolic blood pressure was seen in both the groups. The decrease in urinary protein creatinine ratio was significantly higher in cilnidipine group rather than amlodipine group. Thus, cilnidipine exerted greater antiproteinuric effect than amlodipine.Conclusions: Cilnidipine has antihypertensive effect equivalent to amlodipine but addition of cilnidipine rather than amlodipine to losartan decreased urine protein excretion in diabetic chronic kidney disease patients

Chromate and HF free pretreatment for MAO/electroless nickel plating on AZ31B magnesium alloy

: Microarc oxidation (MAO) coating was developed as an interlayer for the electroless nickel (EN) top coat to improve the corrosion resistance of Mg alloy. Prior to the electroless nickel coating, oxide layer was activated by using NaBH4 solution as a replacement for traditional chromate and HF activation process. The EN coatings were prepared from the alkaline carbonate bath. The prepared coatings were characterized for the surface morphology and composition using Field emission scanning electron microscopy (FE-SEM) attached with Energy dispersive analysis of X-ray (EDX). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies were carried out in non-deaerated 3.5% NaCl solution to find out the corrosion resistance of the coatings. The MAO coating showed porous morphology with micro cracks whereas, MAO/Ni-P coating exhibited dense nodular structure. The composition analysis on the surface of MAO/Ni-P showed 10 wt.% P indicated the high P coating. The cross- sectional images showed good adhesion between MAO and Ni-P layers. This clearly indicates that the present activation process results in dense with uniform pores of MAO coating which supply excellent bonding interface for Ni–P coat. The MAO/EN coating combination showed about 97 times improved corrosion resistance as compared with the substrate and similar behaviour was observed by EIS studies

A surgical study of serological markers such as C-reactive protein and interleukin 6 in response to postoperative infection in patients with open fractures in a tertiary care hospital

To study the response of C-reactive protein (CRP) and interleukin-6 (IL-6) to postoperative infection in patients with open fractures. Thirty patients with open fractures of extremities within 12 hours of injury were included in study. Blood samples were collected for Postoperative infection is a devastating complication of open fractures. The ideal investigation for early diagnosis of infection should be done before surgery and should be accurate, convenient to patient, cause minimal morbidity. Test such as CRP and IL-6 estimation is utilized in this study. CRP and IL 6 estimation on admission, second and fourth post-op day. All patients underwent surgery and reports evaluated. It was observed that CRP peak on post-op day 4 and IL 6 on postoperative day 2 in patients with infection before clinical evidence of infection. This prospective study includes 30 cases, followed up in ward for a week. Various factors regarding clinical presentation, findings of various investigations, operative treatment had been analyzed. The sensitivity of CRP in our study was 100%, and specificity was 42%. The persistent rise of CRP value seen within the infected group was statistically significant (p<0.05). The present clinical study of estimation of CRP and IL 6 to detect postoperative infection in patients after open fractures is an excellent diagnostic test for early detection and management of infection

Radial nerve neurotmesis in closed humeral shaft fracture: unusual case

Radial nerve neurotmesis constitutes a major problem in the treatment of closed fractures of the mid-shaft of the humerus. A case of radial nerve neurotmesis associated with a closed fracture of mid-shaft of the humerus is reported. Radial nerve neurotmesis was found at the fractured site. Early exploration of the nerve and primary internal fixation of the fracture was done which gave a satisfactory result

Prophylactic irradiation of tracts in patients with malignant pleural mesothelioma : an open-label, multicenter, phase III randomized trial

PURPOSE Prophylactic irradiation to the chest wall after diagnostic or therapeutic procedures in patients with malignant pleural mesothelioma (MPM) has been a widespread practice across Europe, although the efficacy of this treatment is uncertain. In this study, we aimed to determine the efficacy of prophylactic radiotherapy in reducing the incidence of chest wall metastases (CWM) after a procedure in MPM. METHODS After undergoing a chest wall procedure, patients with MPM were randomly assigned to receive prophylactic radiotherapy (within 42 days of the procedure) or no radiotherapy. Open thoracotomies, needle biopsies, and indwelling pleural catheters were excluded. Prophylactic radiotherapy was delivered at a dose of 21 Gy in three fractions over three consecutive working days, using a single electron field adapted to maximize coverage of the tract from skin surface to pleura. The primary outcome was the incidence of CWM within 6 months from random assignment, assessed in the intention-to-treat population. Stratification factors included epithelioid histology and intention to give chemotherapy. RESULTS Between July 30, 2012, and December 12, 2015, 375 patients were recruited from 54 centers and randomly assigned to receive prophylactic radiotherapy (n = 186) or no prophylactic radiotherapy (n = 189). Participants were well matched at baseline. No significant difference was seen in the incidence of CWM at 6 months between the prophylactic radiotherapy and no radiotherapy groups (no. [%]: 6 [3.2] v 10 [5.3], respectively; odds ratio, 0.60; 95% CI, 0.17 to 1.86; P = .44). Skin toxicity was the most common radiotherapy-related adverse event in the prophylactic radiotherapy group, with 96 patients (51.6%) receiving grade 1; 19 (10.2%), grade 2; and 1 (0.5%) grade 3 radiation dermatitis (Common Terminology Criteria for Adverse Events, version 4.0). CONCLUSION There is no role for the routine use of prophylactic irradiation to chest wall procedure sites in patients with MPM

Fc-Optimized Anti-CD25 Depletes Tumor-Infiltrating Regulatory T Cells and Synergizes with PD-1 Blockade to Eradicate Established Tumors

CD25 is expressed at high levels on regulatory T (Treg) cells and was initially proposed as a target for cancer immunotherapy. However, anti-CD25 antibodies have displayed limited activity against established tumors. We demonstrated that CD25 expression is largely restricted to tumor-infiltrating Treg cells in mice and humans. While existing anti-CD25 antibodies were observed to deplete Treg cells in the periphery, upregulation of the inhibitory Fc gamma receptor (FcγR) IIb at the tumor site prevented intra-tumoral Treg cell depletion, which may underlie the lack of anti-tumor activity previously observed in pre-clinical models. Use of an anti-CD25 antibody with enhanced binding to activating FcγRs led to effective depletion of tumor-infiltrating Treg cells, increased effector to Treg cell ratios, and improved control of established tumors. Combination with anti-programmed cell death protein-1 antibodies promoted complete tumor rejection, demonstrating the relevance of CD25 as a therapeutic target and promising substrate for future combination approaches in immune-oncology

Studies on electrodeposited nickel–yttria doped ceria composite coatings

Incorporation of ceria particles into the Ni matrix was found to improve the corrosion resistance of pure Ni coatings. With the aim of further improving the corrosion resistance of Ni-ceria, yttria was doped with ceria and used as distributed phase. About 8-mol% yttria doped ceria (8YDC) particles synthesized by a solution combustion process were dispersed in a nickel sulfamate bath and electrodeposition was carried out to prepare Ni–8YDC composite coatings at various current densities. The microhardness of the composite coatings was determined. Optical microscopy confirmed the incorporation of 8YDC particles into the Ni matrix. Potentiodynamic polarization and electrochemical impedance spectroscopy were used to characterize the corrosion behavior of the Ni–8YDC coatings. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX) were used to characterize the corroded samples. The results were compared with those for Ni and Ni–CeO2 coatings. The wear behavior of Ni–8YDC was studied. Wear tracks were characterized by MicroRaman Spectroscop